Is Elevated Acceptable?

Is a new high-capacity transit system worth the visual encumberments it will cause? Should the views of a beautiful tropical city be obstructed for the benefit of passengers on public transportation? That’s the question now being debated in Honolulu, which is planning an elevated rail line that will run throughout the city.

Hawaii’s biggest city is planning a 20-mile transit line, running from Kapolei in the west to Ala Moana Center downtown, via Waipahu and the airport. Honolulu’s density is high enough to require a rail system with a fully independent right-of-way; the city’s The Bus transit system already carries an average of 225,000 riders a day, and the new line is expected to transport a full 95,000 of those passengers by 2030. The first phase of the system is expected to be completed by 2018 at a cost of $5.8 billion, with construction possibly beginning late this year.

Yet, while the elevated alignment has been set in stone for more than a year now, the city’s chapter of the American Institute of Architects is now asking the city to run the system at ground level downtown so as not to obstruct views in that dense waterfront area. The architects argue that Honolulu’s landscape will be decimated by the concrete guideways. The elevated route would run on an aerial viaduct 30 feet off the ground (visualized in the before-and-after pictures above). An underground subway isn’t an economically realistic option.

The negative consequence of moving the trains to ground level would be significant: overall trip time would increase by 10 minutes and automated operation would be impossible. If current plans play out, on the other hand, Honolulu’s system would probably operate like Vancouver’s SkyTrain, which has driverless vehicles running on third rail electric current. More standard light rail lines require drivers and overhead catenary, both of which increase operating costs, but which allow for street-running trains.

There’s no doubt that the elevated guideways aren’t going to be pretty — nobody likes huge concrete bridges spanning neighborhoods, which may find themselves plunged into occasional daytime darkness depending on the position of the sun. In addition, stations will be more difficult to access because they’ll be elevated over the sidewalk.

But the advantages of overhead rails come in the form of speed, because a SkyTrain-like system never encounters traffic, whereas LRT lines are all too frequently delayed by vehicles getting in the way. Driverless systems also have higher and more stable acceleration rates. Transit’s travel time benefits over automobile commuting is debatable, reducing public transport’s attractiveness to potential riders. Any effort to increase the speed of transit offerings would likely increase the number of people switching modes.

It’s a wash, then.

Are there potential compromises? One option is opting for extensive viaduct treatments downtown that would make the elevated line look less imposing and sinister. If the city invested in exciting artwork and lighting treatments along the bottom of the guideway, an aerial track might be something of an attraction. Similarly, a ground-level line could function well if fully separated from automobile lanes and given traffic signal priority at every intersection, modifications that would eliminate at least some of that 10-minute gap between the two alignment options. On the other hand, that would require a significant drop in the level of service offered to car drivers in areas near the line, something that’s not the easiest thing for which to advocate.

No matter whether an elevated or ground line is picked, though, the city would do well to consider seriously about how to minimize its respective drawbacks. Without that thinking process, Honolulu won’t get as good of a transit corridor as it deserves.

On the other hand, those riding on an elevated transit system will have a better view of the surrounding landscape than those at ground level currently do.

I don’t know why they want to run it in the middle of downtown, though. Can’t they put the stations on the edge of honolulu and make people walk a few feet? Or else, run the elevated, automated systems to the edge of the city and then have street cars or BRT to take people the rest of the way.

Those pics are interesting — when’s the last time anyone in North America built an elevated transit line suspended over a city street like this? Reminds me of a more modern version of some NYC elevated lines.

The image brings to mind something I’ve been wondering about for a while: why are modern concrete structures so big and bulky? This is most obvious in highway viaducts: the ones built 40-50 years ago are much slimmer and less visually obtrusive than similar ones built today. Near where I live, a 57-year-old two-lane bridge over an expressway was recently replaced. There was no capacity expansion: two old lanes became two new lanes. But the new structure is probably three times the size and weight of the old one — and this is in a rural location with no seismic risk.

It makes one wonder if “modern” construction standards were developed to favor the concrete industry. It may also explain part of the spectacular increase in public construction costs and timescales over the last 30 years.

That Honolulu elevated is far uglier and bulkier than what would have been built even thirty years ago. (A hundred years ago it would have been a slim steel structure and not concrete at all.) Why?

The Overhead Wire featured the elevated tram-train in The Netherlands. It effectively features a very attractive elevated system; actually it looks like a piece of art.

Maybe Honolulu could develop something that looks like a wave for their elevated system. I’m no architect, but that sounds neat anyways.

Also, at Switching Modes there was recently a feature an elevated cable cars. The advantage is that the system is pooled by a cable so the train cars are lighter (no need for an engine) and the elevated guideway requires fewer, smaller supports. Venezuela is building one of these system, Las Vegas already has one, and BART in the Bay Area is looking at using this technology as well. (for images visit this link).

However, elevated cable cars are probably not appropriate for this line in Honolulu. They cannot cover 20 miles, nor carry the passenger volumes required for this system.

BUT – what you might be able to do (I’m not an expert on this project), is use the cable technology through downtown, and use a standard metro service on an elevated guideway next to the freeway further inland. The metro service would connect to the cable car line at both ends of the line.

This system would address the aesthetic problem of an elevated system, more capacity would added through downtown where traffic will be heaviest, the transit system could reach more people, and the trip for commuters going through downtown their trip could be even faster because there could be fewer stops. The system could use the same fair collection system and be designed for cross-platform transfers or the transfer platforms could be stacked on top of each other so that all that is needed is single story escalator ride to get between trains.

Trains and traffic don’t mix well; not when you have just one main artery through an urban area like that.

This is not a wash in any way. There is no good way to incorporate an elevated track into an attractive, vibrant city environment. These tracks destroy neighborhoods, which is why you cities all over America removing them.
Solving these problems is going to be a lot harder and more complex than people let on. You can’t just myopically say “build more rail” and then start obsessing over minutia like automated operation, average trip speeds, etc. This is the same internal engineering obsession that has lead highway planners over the decades to destroy America in the name of “efficiency.” You don’t create good cities just because the blunt instrument you wield is a rail line and not a highway.
I’m glad somebody, somewhere is trying to raise awareness of these issues.

Most of the line runs down highway medians – so that is why they can’t put commercial space under it – there are already cars there. A lot of it runs through commercial areas too. Best Buy on one side and a 1960’s strip mall on the other. Funny, the guideway kind of fits in.

I think the comment on pristine environment is a good one to think about – there has been a lot of development pressure on Oahu (slowwed down right now). Having decent reliable fast transit in about the best tool left to try and keep that development within the UGB. You don’t build this and a lot more of the overall land is going to be covered in suburban-style development.

Of course elevated lines can be made to fit in an urban environment it is just that most planners are too lazy or unimaginative to work. It just takes some creativity and a willingness to give it a try. It is not like an elevated transit line has anywhere near the impact of an elevated freeway.

Underneath the guideway is a perfect place for walkways or patios as it is protected from the sun and rain. One of the best public spaces in Vancouver is Granville Island which is underneath a huge bridge and its approaches. There are popular greenways under the SkyTrain guideways as well. London has built some really funky restaurants and shops under their elevated railway.

jfruf: Last time someone built such an elevated line? In the US? Oh, about 1993 when Chicago’s Orange Line opened. In Canada? 2009 when the Canada Line of Vancouver’s SkyTrain opened.

As for Rockfish’s assertion that “There is no good way to incorporate an elevated track into an attractive, vibrant city environment. These tracks destroy neighborhoods, which is why you cities all over America removing them.” What utter bilge. I think Chicago, Philadelphia, DC, and Vancouver all prove that elevated tracks fit well in an urban environment and do not destroy neighborhoods. For more evidence, look at most train systems in Germany. Or most of the subway in Brooklyn, Queens, and the Bronx. I could go on, but I have a suspicion you don’t actually live near elevated tracks.

Most of the Orange line, however, is on RR ROW, either at grade or viaduct, rather than elevated structure, mainly for connections between ROW and existing track, which is why it was able to be built. Boston, however, seems to have gotten rid of most of their els, unlike other cities (if I remember right, some El removal in Queens actually killed off local business), though some in Chicago would like to have it put underground.

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are discussing online. You actually understand how to bring an issue to light and make
it important. A lot more people really need to read this and understand
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